Commit Graph

790 Commits

Author SHA1 Message Date
Markus Armbruster
6cc0667d9b Tweak a few "Parameter 'NAME' expects THING" error message
Change to "expects a THING" where that's an obvious improvement

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20201113082626.2725812-11-armbru@redhat.com>
2020-12-10 17:16:44 +01:00
Markus Armbruster
b0d7be2a62 block: Improve some block-commit, block-stream error messages
block-commit defaults @base-node to the deepest backing image.  When
there is none, it fails with "Base 'NULL' not found".  Improve to
"There is no backing image".

block-commit and block-stream reject a @base argument that doesn't
resolve with "Base 'BASE' not found".  Commit 6b33f3ae8b "qemu-img:
Improve commit invalid base message" improved this message in
qemu-img.  Improve it here, too: "Can't find '%s' in the backing
chain".

QERR_BASE_NOT_FOUND is now unused.  Drop.

Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Max Reitz <mreitz@redhat.com>
Cc: qemu-block@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20201113082626.2725812-4-armbru@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2020-12-10 17:16:44 +01:00
Kevin Wolf
eb94b81a94 block: Convert 'block_resize' to coroutine
block_resize performs some I/O that could potentially take quite some
time, so use it as an example for the new 'coroutine': true annotation
in the QAPI schema.

bdrv_truncate() requires that we're already in the right AioContext for
the BlockDriverState if called in coroutine context. So instead of just
taking the AioContext lock, move the QMP handler coroutine to the
context.

Call blk_unref() only after switching back because blk_unref() may only
be called in the main thread.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20201005155855.256490-15-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-10-09 07:08:20 +02:00
Pavel Dovgalyuk
b39847a505 migration: introduce icount field for snapshots
Saving icount as a parameters of the snapshot allows navigation between
them in the execution replay scenario.
This information can be used for finding a specific snapshot for proceeding
the recorded execution to the specific moment of the time.
E.g., 'reverse step' action (introduced in one of the following patches)
needs to load the nearest snapshot which is prior to the current moment
of time.
This patch also updates snapshot test which verifies qemu monitor output.

Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
Acked-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>

--

v4 changes:
 - squashed format update with test output update
v7 changes:
 - introduced the spaces between the fields in snapshot info output
 - updated the test to match new field widths
Message-Id: <160174518865.12451.14327573383978752463.stgit@pasha-ThinkPad-X280>

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-06 08:34:49 +02:00
Stefan Hajnoczi
d73415a315 qemu/atomic.h: rename atomic_ to qatomic_
clang's C11 atomic_fetch_*() functions only take a C11 atomic type
pointer argument. QEMU uses direct types (int, etc) and this causes a
compiler error when a QEMU code calls these functions in a source file
that also included <stdatomic.h> via a system header file:

  $ CC=clang CXX=clang++ ./configure ... && make
  ../util/async.c:79:17: error: address argument to atomic operation must be a pointer to _Atomic type ('unsigned int *' invalid)

Avoid using atomic_*() names in QEMU's atomic.h since that namespace is
used by <stdatomic.h>. Prefix QEMU's APIs with 'q' so that atomic.h
and <stdatomic.h> can co-exist. I checked /usr/include on my machine and
searched GitHub for existing "qatomic_" users but there seem to be none.

This patch was generated using:

  $ git grep -h -o '\<atomic\(64\)\?_[a-z0-9_]\+' include/qemu/atomic.h | \
    sort -u >/tmp/changed_identifiers
  $ for identifier in $(</tmp/changed_identifiers); do
        sed -i "s%\<$identifier\>%q$identifier%g" \
            $(git grep -I -l "\<$identifier\>")
    done

I manually fixed line-wrap issues and misaligned rST tables.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200923105646.47864-1-stefanha@redhat.com>
2020-09-23 16:07:44 +01:00
Max Reitz
05ea385afd blockdev: Fix active commit choice
We have to perform an active commit whenever the top node has a parent
that has taken the WRITE permission on it.

This means that block-commit's @backing-file parameter is no longer
allowed for such nodes, and that users will have to issue a
block-job-complete command.  Neither should pose a problem in practice,
because this case was basically just broken until now.

(Since this commit already touches block-commit's documentation, it also
moves up the chunk explaining general block-commit behavior that for
some reason was situated under @backing-file.)

Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-07 12:31:31 +02:00
Max Reitz
9a71b9de3f commit: Deal with filters
This includes some permission limiting (for example, we only need to
take the RESIZE permission if the base is smaller than the top).

Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-07 12:31:31 +02:00
Max Reitz
2b088c60bb backup: Deal with filters
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:31:31 +02:00
Max Reitz
3f072a7fb7 mirror: Deal with filters
This includes some permission limiting (for example, we only need to
take the RESIZE permission for active commits where the base is smaller
than the top).

base_overlay is introduced so we can query bdrv_is_allocated_above() on
it - we cannot do that with base itself, because a filter's block_status
is the same as its child node, so if there are filters on base,
bdrv_is_allocated_above() on base would return information including
base.

Use this opportunity to rename qmp_drive_mirror()'s "source" BDS to
"target_backing_bs", because that is what it really refers to.

Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-07 12:31:31 +02:00
Max Reitz
7cc734a9ea blockdev: Use CAF in external_snapshot_prepare()
This allows us to differentiate between filters and nodes with COW
backing files: Filters cannot be used as overlays at all (for this
function).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:31:31 +02:00
Max Reitz
67acfd2188 stream: Deal with filters
Because of the (not so recent anymore) changes that make the stream job
independent of the base node and instead track the node above it, we
have to split that "bottom" node into two cases: The bottom COW node,
and the node directly above the base node (which may be an R/W filter
or the bottom COW node).

Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-07 12:31:31 +02:00
Eric Blake
e54ee1b385 block: Add support to warn on backing file change without format
For now, this is a mechanical addition; all callers pass false. But
the next patch will use it to improve 'qemu-img rebase -u' when
selecting a backing file with no format.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Message-Id: <20200706203954.341758-10-eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-14 15:18:59 +02:00
Markus Armbruster
992861fb1e error: Eliminate error_propagate() manually
When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away.  The previous two commits did that for sufficiently simple
cases with Coccinelle.  Do it for several more manually.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-37-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
af175e85f9 error: Eliminate error_propagate() with Coccinelle, part 2
When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away.  The previous commit did that with a Coccinelle script I
consider fairly trustworthy.  This commit uses the same script with
the matching of return taken out, i.e. we convert

    if (!foo(..., &err)) {
        ...
        error_propagate(errp, err);
        ...
    }

to

    if (!foo(..., errp)) {
        ...
        ...
    }

This is unsound: @err could still be read between afterwards.  I don't
know how to express "no read of @err without an intervening write" in
Coccinelle.  Instead, I manually double-checked for uses of @err.

Suboptimal line breaks tweaked manually.  qdev_realize() simplified
further to placate scripts/checkpatch.pl.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-36-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
668f62ec62 error: Eliminate error_propagate() with Coccinelle, part 1
When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away.  Convert

    if (!foo(..., &err)) {
        ...
        error_propagate(errp, err);
        ...
        return ...
    }

to

    if (!foo(..., errp)) {
        ...
        ...
        return ...
    }

where nothing else needs @err.  Coccinelle script:

    @rule1 forall@
    identifier fun, err, errp, lbl;
    expression list args, args2;
    binary operator op;
    constant c1, c2;
    symbol false;
    @@
         if (
    (
    -        fun(args, &err, args2)
    +        fun(args, errp, args2)
    |
    -        !fun(args, &err, args2)
    +        !fun(args, errp, args2)
    |
    -        fun(args, &err, args2) op c1
    +        fun(args, errp, args2) op c1
    )
            )
         {
             ... when != err
                 when != lbl:
                 when strict
    -        error_propagate(errp, err);
             ... when != err
    (
             return;
    |
             return c2;
    |
             return false;
    )
         }

    @rule2 forall@
    identifier fun, err, errp, lbl;
    expression list args, args2;
    expression var;
    binary operator op;
    constant c1, c2;
    symbol false;
    @@
    -    var = fun(args, &err, args2);
    +    var = fun(args, errp, args2);
         ... when != err
         if (
    (
             var
    |
             !var
    |
             var op c1
    )
            )
         {
             ... when != err
                 when != lbl:
                 when strict
    -        error_propagate(errp, err);
             ... when != err
    (
             return;
    |
             return c2;
    |
             return false;
    |
             return var;
    )
         }

    @depends on rule1 || rule2@
    identifier err;
    @@
    -    Error *err = NULL;
         ... when != err

Not exactly elegant, I'm afraid.

The "when != lbl:" is necessary to avoid transforming

         if (fun(args, &err)) {
             goto out
         }
         ...
     out:
         error_propagate(errp, err);

even though other paths to label out still need the error_propagate().
For an actual example, see sclp_realize().

Without the "when strict", Coccinelle transforms vfio_msix_setup(),
incorrectly.  I don't know what exactly "when strict" does, only that
it helps here.

The match of return is narrower than what I want, but I can't figure
out how to express "return where the operand doesn't use @err".  For
an example where it's too narrow, see vfio_intx_enable().

Silently fails to convert hw/arm/armsse.c, because Coccinelle gets
confused by ARMSSE being used both as typedef and function-like macro
there.  Converted manually.

Line breaks tidied up manually.  One nested declaration of @local_err
deleted manually.  Preexisting unwanted blank line dropped in
hw/riscv/sifive_e.c.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-35-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
235e59cf03 qemu-option: Use returned bool to check for failure
The previous commit enables conversion of

    foo(..., &err);
    if (err) {
        ...
    }

to

    if (!foo(..., &err)) {
        ...
    }

for QemuOpts functions that now return true / false on success /
error.  Coccinelle script:

    @@
    identifier fun = {
        opts_do_parse, parse_option_bool, parse_option_number,
        parse_option_size, qemu_opt_parse, qemu_opt_rename, qemu_opt_set,
        qemu_opt_set_bool, qemu_opt_set_number, qemu_opts_absorb_qdict,
        qemu_opts_do_parse, qemu_opts_from_qdict_entry, qemu_opts_set,
        qemu_opts_validate
    };
    expression list args, args2;
    typedef Error;
    Error *err;
    @@
    -    fun(args, &err, args2);
    -    if (err)
    +    if (!fun(args, &err, args2))
         {
             ...
         }

A few line breaks tidied up manually.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-15-armbru@redhat.com>
[Conflict with commit 0b6786a9c1 "block/amend: refactor qcow2 amend
options" resolved by rerunning Coccinelle on master's version]
2020-07-10 15:17:35 +02:00
Markus Armbruster
c75d7f7191 qemu-option: Make functions taking Error ** return bool, not void
See recent commit "error: Document Error API usage rules" for
rationale.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-14-armbru@redhat.com>
2020-07-10 15:01:06 +02:00
Markus Armbruster
c6ecec43b2 qemu-option: Check return value instead of @err where convenient
Convert uses like

    opts = qemu_opts_create(..., &err);
    if (err) {
        ...
    }

to

    opts = qemu_opts_create(..., errp);
    if (!opts) {
        ...
    }

Eliminate error_propagate() that are now unnecessary.  Delete @err
that are now unused.

Note that we can't drop parallels_open()'s error_propagate() here.  We
continue to execute it even in the converted case.  It's a no-op then:
local_err is null.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <20200707160613.848843-8-armbru@redhat.com>
2020-07-10 15:01:06 +02:00
Markus Armbruster
a1b40bda08 blockdev: Deprecate -drive with bogus interface type
Drives with interface types other than if=none are for onboard
devices.  Unfortunately, any such drives the board doesn't pick up can
still be used with -device, like this:

    $ qemu-system-x86_64 -nodefaults -display none -S -drive if=floppy,id=bogus,unit=7 -device ide-cd,drive=bogus -monitor stdio
    QEMU 5.0.50 monitor - type 'help' for more information
    (qemu) info block
    bogus: [not inserted]
	Attached to:      /machine/peripheral-anon/device[0]
	Removable device: not locked, tray closed
    (qemu) info qtree
    bus: main-system-bus
      type System
      [...]
	    bus: ide.1
	      type IDE
	      dev: ide-cd, id ""
--->		drive = "bogus"
		[...]
		unit = 0 (0x0)
      [...]

This kind of abuse has always worked.  Deprecate it:

    qemu-system-x86_64: -drive if=floppy,id=bogus,unit=7: warning: bogus if=floppy is deprecated, use if=none

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200622094227.1271650-9-armbru@redhat.com>
2020-06-23 16:07:07 +02:00
Eric Blake
bb4e58c613 blockdev: Split off basic bitmap operations for qemu-img
Upcoming patches want to add some basic bitmap manipulation abilities
to qemu-img.  But blockdev.o is too heavyweight to link into qemu-img
(among other things, it would drag in block jobs and transaction
support - qemu-img does offline manipulation, where atomicity is less
important because there are no concurrent modifications to compete
with), so it's time to split off the bare bones of what we will need
into a new file block/monitor/bitmap-qmp-cmds.o.

This is sufficient to expose 6 QMP commands for use by qemu-img (add,
remove, clear, enable, disable, merge), as well as move the three
helper functions touched in the previous patch.  Regarding
MAINTAINERS, the new file is automatically part of block core, but
also makes sense as related to other dirty bitmap files.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200513011648.166876-6-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2020-05-19 10:32:14 -05:00
Eric Blake
c6996cf9a6 blockdev: Promote several bitmap functions to non-static
The next patch will split blockdev.c, which will require accessing
some previously-static functions from more than one .c file.  But part
of promoting a function to public is picking a naming scheme that does
not reek of exposing too many internals (two of the three functions
were named starting with 'do_').  To make future code motion easier,
perform the function rename and non-static promotion into its own
patch.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200513011648.166876-5-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2020-05-19 10:32:14 -05:00
Eric Blake
a3aeeab557 block: Add blk_new_with_bs() helper
There are several callers that need to create a new block backend from
an existing BDS; make the task slightly easier with a common helper
routine.

Suggested-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200424190903.522087-2-eblake@redhat.com>
[mreitz: Set @ret only in error paths, see
 https://lists.nongnu.org/archive/html/qemu-block/2020-04/msg01216.html]
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200428192648.749066-2-eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-05-05 13:17:36 +02:00
Kevin Wolf
8c6242b6f3 block-backend: Add flags to blk_truncate()
Now that node level interface bdrv_truncate() supports passing request
flags to the block driver, expose this on the BlockBackend level, too.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200424125448.63318-4-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-04-30 17:51:07 +02:00
Markus Armbruster
1f5842487a qapi: Only input visitors can actually fail
The previous few commits have made this more obvious, and removed the
one exception.  Time to clarify the documentation, and drop dead error
checking.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200424084338.26803-13-armbru@redhat.com>
2020-04-30 07:26:40 +02:00
Stefan Reiter
b660a84bbb job: take each job's lock individually in job_txn_apply
All callers of job_txn_apply hold a single job's lock, but different
jobs within a transaction can have different contexts, thus we need to
lock each one individually before applying the callback function.

Similar to job_completed_txn_abort this also requires releasing the
caller's context before and reacquiring it after to avoid recursive
locks which might break AIO_WAIT_WHILE in the callback. This is safe, since
existing code would already have to take this into account, lest
job_completed_txn_abort might have broken.

This also brings to light a different issue: When a callback function in
job_txn_apply moves it's job to a different AIO context, callers will
try to release the wrong lock (now that we re-acquire the lock
correctly, previously it would just continue with the old lock, leaving
the job unlocked for the rest of the return path). Fix this by not caching
the job's context.

This is only necessary for qmp_block_job_finalize, qmp_job_finalize and
job_exit, since everyone else calls through job_exit.

One test needed adapting, since it calls job_finalize directly, so it
manually needs to acquire the correct context.

Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
Message-Id: <20200407115651.69472-2-s.reiter@proxmox.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-04-07 14:34:47 +02:00
Kevin Wolf
30dd65f307 block: Fix cross-AioContext blockdev-snapshot
external_snapshot_prepare() tries to move the overlay to the AioContext
of the backing file (the snapshotted node). However, it's possible that
this doesn't work, but the backing file can instead be moved to the
overlay's AioContext (e.g. opening the backing chain for a mirror
target).

bdrv_append() already indirectly uses bdrv_attach_node(), which takes
care to move nodes to make sure they use the same AioContext and which
tries both directions.

So the problem has a simple fix: Just delete the unnecessary extra
bdrv_try_set_aio_context() call in external_snapshot_prepare() and
instead assert in bdrv_append() that both nodes were indeed moved to the
same AioContext.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200310113831.27293-6-kwolf@redhat.com>
Tested-by: Peter Krempa <pkrempa@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-03-11 15:54:38 +01:00
Kevin Wolf
d29d3d1f80 block: Relax restrictions for blockdev-snapshot
blockdev-snapshot returned an error if the overlay was already in use,
which it defined as having any BlockBackend parent. This is in fact both
too strict (some parents can tolerate the change of visible data caused
by attaching a backing file) and too loose (some non-BlockBackend
parents may not be happy with it).

One important use case that is prevented by the too strict check is live
storage migration with blockdev-mirror. Here, the target node is
usually opened without a backing file so that the active layer is
mirrored while its backing chain can be copied in the background.

The backing chain should be attached to the mirror target node when
finalising the job, just before switching the users of the source node
to the new copy (at which point the mirror job still has a reference to
the node). drive-mirror did this automatically, but with blockdev-mirror
this is the job of the QMP client, so it needs a way to do this.

blockdev-snapshot is the obvious way, so this patch makes it work in
this scenario. The new condition is that no parent uses CONSISTENT_READ
permissions. This will ensure that the operation will still be blocked
when the node is attached to the guest device, so blockdev-snapshot
remains safe.

(For the sake of completeness, x-blockdev-reopen can be used to achieve
the same, however it is a big hammer, performs the graph change
completely unchecked and is still experimental. So even with the option
of using x-blockdev-reopen, there are reasons why blockdev-snapshot
should be able to perform this operation.)

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200310113831.27293-3-kwolf@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Tested-by: Peter Krempa <pkrempa@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-03-11 15:54:38 +01:00
Maxim Levitsky
89802d5ae7 monitor/hmp: Move hmp_drive_add_node to block-hmp-cmds.c
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20200308092440.23564-12-mlevitsk@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2020-03-09 18:20:22 +00:00
Maxim Levitsky
a1edae276a monitor/hmp: move hmp_drive_del and hmp_commit to block-hmp-cmds.c
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20200308092440.23564-5-mlevitsk@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2020-03-09 18:05:33 +00:00
Kevin Wolf
12c929bca2 block: Move system emulator QMP commands to block/qapi-sysemu.c
These commands make only sense for system emulators and their
implementations call functions that don't exist in tools (e.g. to
resolve qdev IDs). Move them out so that blockdev.c can be linked to
qemu-storage-daemon.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200224143008.13362-4-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-03-06 17:15:38 +01:00
Peter Krempa
facda5443f qapi: Allow getting flat output from 'query-named-block-nodes'
When a management application manages node names there's no reason to
recurse into backing images in the output of query-named-block-nodes.

Add a parameter to the command which will return just the top level
structs.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Message-Id: <4470f8c779abc404dcf65e375db195cd91a80651.1579509782.git.pkrempa@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[mreitz: Fixed coding style]
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-02-20 16:43:42 +01:00
Max Reitz
7607074f42 blockdev: Allow resizing everywhere
Block nodes that do not allow resizing should not share BLK_PERM_RESIZE.
It does not matter whether they are the first non-filter in their chain
or not.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200218103454.296704-3-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-02-18 11:55:39 +01:00
Max Reitz
ca08d937e8 blockdev: Allow external snapshots everywhere
There is no good reason why we would allow external snapshots only on
the first non-filter node in a chain.  Parent BDSs should not care
whether their child is replaced by a snapshot.  (If they do care, they
should announce that via freezing the chain, which is checked in
bdrv_append() through bdrv_set_backing_hd().)

Before we had bdrv_is_first_non_filter() here (since 212a5a8f09), there
was a special function bdrv_check_ext_snapshot() that allowed snapshots
by default, but block drivers could override this.  Only blkverify did
so, however.

It is not clear to me why blkverify would do so; maybe just so that the
testee block driver would not be replaced.  The introducing commit
f6186f49e2 does not explain why.  Maybe because 08b24cfe37 would have
been the correct solution?  (Which adds a .supports_backing check.)

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200218103454.296704-2-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-02-18 11:55:38 +01:00
Kevin Wolf
8faad1c7fb commit: Expose on-error option in QMP
Now that the error handling in the common block job is fixed, we can
expose the on-error option in QMP instead of hard-coding it as 'report'
in qmp_block_commit().

This fulfills the promise that the old comment in that function made,
even if a bit later than expected: "This will be part of the QMP
command, if/when the BlockdevOnError change for blkmirror makes it in".

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200214200812.28180-7-kwolf@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-02-18 10:53:56 +01:00
Aarushi Mehta
f80f267373 blockdev: adds bdrv_parse_aio to use io_uring
Signed-off-by: Aarushi Mehta <mehta.aaru20@gmail.com>
Acked-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200120141858.587874-8-stefanha@redhat.com
Message-Id: <20200120141858.587874-8-stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-01-30 20:59:41 +00:00
Sergio Lopez
377410f6fb blockdev: Return bs to the proper context on snapshot abort
external_snapshot_abort() calls to bdrv_set_backing_hd(), which
returns state->old_bs to the main AioContext, as it's intended to be
used then the BDS is going to be released. As that's not the case when
aborting an external snapshot, return it to the AioContext it was
before the call.

This issue can be triggered by issuing a transaction with two actions,
a proper blockdev-snapshot-sync and a bogus one, so the second will
trigger a transaction abort. This results in a crash with an stack
trace like this one:

 #0  0x00007fa1048b28df in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
 #1  0x00007fa10489ccf5 in __GI_abort () at abort.c:79
 #2  0x00007fa10489cbc9 in __assert_fail_base
     (fmt=0x7fa104a03300 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", assertion=0x5572240b44d8 "bdrv_get_aio_context(old_bs) == bdrv_get_aio_context(new_bs)", file=0x557224014d30 "block.c", line=2240, function=<optimized out>) at assert.c:92
 #3  0x00007fa1048aae96 in __GI___assert_fail
     (assertion=assertion@entry=0x5572240b44d8 "bdrv_get_aio_context(old_bs) == bdrv_get_aio_context(new_bs)", file=file@entry=0x557224014d30 "block.c", line=line@entry=2240, function=function@entry=0x5572240b5d60 <__PRETTY_FUNCTION__.31620> "bdrv_replace_child_noperm") at assert.c:101
 #4  0x0000557223e631f8 in bdrv_replace_child_noperm (child=0x557225b9c980, new_bs=new_bs@entry=0x557225c42e40) at block.c:2240
 #5  0x0000557223e68be7 in bdrv_replace_node (from=0x557226951a60, to=0x557225c42e40, errp=0x5572247d6138 <error_abort>) at block.c:4196
 #6  0x0000557223d069c4 in external_snapshot_abort (common=0x557225d7e170) at blockdev.c:1731
 #7  0x0000557223d069c4 in external_snapshot_abort (common=0x557225d7e170) at blockdev.c:1717
 #8  0x0000557223d09013 in qmp_transaction (dev_list=<optimized out>, has_props=<optimized out>, props=0x557225cc7d70, errp=errp@entry=0x7ffe704c0c98) at blockdev.c:2360
 #9  0x0000557223e32085 in qmp_marshal_transaction (args=<optimized out>, ret=<optimized out>, errp=0x7ffe704c0d08) at qapi/qapi-commands-transaction.c:44
 #10 0x0000557223ee798c in do_qmp_dispatch (errp=0x7ffe704c0d00, allow_oob=<optimized out>, request=<optimized out>, cmds=0x5572247d3cc0 <qmp_commands>) at qapi/qmp-dispatch.c:132
 #11 0x0000557223ee798c in qmp_dispatch (cmds=0x5572247d3cc0 <qmp_commands>, request=<optimized out>, allow_oob=<optimized out>) at qapi/qmp-dispatch.c:175
 #12 0x0000557223e06141 in monitor_qmp_dispatch (mon=0x557225c69ff0, req=<optimized out>) at monitor/qmp.c:120
 #13 0x0000557223e0678a in monitor_qmp_bh_dispatcher (data=<optimized out>) at monitor/qmp.c:209
 #14 0x0000557223f2f366 in aio_bh_call (bh=0x557225b9dc60) at util/async.c:117
 #15 0x0000557223f2f366 in aio_bh_poll (ctx=ctx@entry=0x557225b9c840) at util/async.c:117
 #16 0x0000557223f32754 in aio_dispatch (ctx=0x557225b9c840) at util/aio-posix.c:459
 #17 0x0000557223f2f242 in aio_ctx_dispatch (source=<optimized out>, callback=<optimized out>, user_data=<optimized out>) at util/async.c:260
 #18 0x00007fa10913467d in g_main_dispatch (context=0x557225c28e80) at gmain.c:3176
 #19 0x00007fa10913467d in g_main_context_dispatch (context=context@entry=0x557225c28e80) at gmain.c:3829
 #20 0x0000557223f31808 in glib_pollfds_poll () at util/main-loop.c:219
 #21 0x0000557223f31808 in os_host_main_loop_wait (timeout=<optimized out>) at util/main-loop.c:242
 #22 0x0000557223f31808 in main_loop_wait (nonblocking=<optimized out>) at util/main-loop.c:518
 #23 0x0000557223d13201 in main_loop () at vl.c:1828
 #24 0x0000557223bbfb82 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4504

RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1779036
Signed-off-by: Sergio Lopez <slp@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-01-27 17:19:53 +01:00
Sergio Lopez
91005a495e blockdev: Acquire AioContext on dirty bitmap functions
Dirty map addition and removal functions are not acquiring to BDS
AioContext, while they may call to code that expects it to be
acquired.

This may trigger a crash with a stack trace like this one:

 #0  0x00007f0ef146370f in __GI_raise (sig=sig@entry=6)
     at ../sysdeps/unix/sysv/linux/raise.c:50
 #1  0x00007f0ef144db25 in __GI_abort () at abort.c:79
 #2  0x0000565022294dce in error_exit
     (err=<optimized out>, msg=msg@entry=0x56502243a730 <__func__.16350> "qemu_mutex_unlock_impl") at util/qemu-thread-posix.c:36
 #3  0x00005650222950ba in qemu_mutex_unlock_impl
     (mutex=mutex@entry=0x5650244b0240, file=file@entry=0x565022439adf "util/async.c", line=line@entry=526) at util/qemu-thread-posix.c:108
 #4  0x0000565022290029 in aio_context_release
     (ctx=ctx@entry=0x5650244b01e0) at util/async.c:526
 #5  0x000056502221cd08 in bdrv_can_store_new_dirty_bitmap
     (bs=bs@entry=0x5650244dc820, name=name@entry=0x56502481d360 "bitmap1", granularity=granularity@entry=65536, errp=errp@entry=0x7fff22831718)
     at block/dirty-bitmap.c:542
 #6  0x000056502206ae53 in qmp_block_dirty_bitmap_add
     (errp=0x7fff22831718, disabled=false, has_disabled=<optimized out>, persistent=<optimized out>, has_persistent=true, granularity=65536, has_granularity=<optimized out>, name=0x56502481d360 "bitmap1", node=<optimized out>) at blockdev.c:2894
 #7  0x000056502206ae53 in qmp_block_dirty_bitmap_add
     (node=<optimized out>, name=0x56502481d360 "bitmap1", has_granularity=<optimized out>, granularity=<optimized out>, has_persistent=true, persistent=<optimized out>, has_disabled=false, disabled=false, errp=0x7fff22831718) at blockdev.c:2856
 #8  0x00005650221847a3 in qmp_marshal_block_dirty_bitmap_add
     (args=<optimized out>, ret=<optimized out>, errp=0x7fff22831798)
     at qapi/qapi-commands-block-core.c:651
 #9  0x0000565022247e6c in do_qmp_dispatch
     (errp=0x7fff22831790, allow_oob=<optimized out>, request=<optimized out>, cmds=0x565022b32d60 <qmp_commands>) at qapi/qmp-dispatch.c:132
 #10 0x0000565022247e6c in qmp_dispatch
     (cmds=0x565022b32d60 <qmp_commands>, request=<optimized out>, allow_oob=<optimized out>) at qapi/qmp-dispatch.c:175
 #11 0x0000565022166061 in monitor_qmp_dispatch
     (mon=0x56502450faa0, req=<optimized out>) at monitor/qmp.c:145
 #12 0x00005650221666fa in monitor_qmp_bh_dispatcher
     (data=<optimized out>) at monitor/qmp.c:234
 #13 0x000056502228f866 in aio_bh_call (bh=0x56502440eae0)
     at util/async.c:117
 #14 0x000056502228f866 in aio_bh_poll (ctx=ctx@entry=0x56502440d7a0)
     at util/async.c:117
 #15 0x0000565022292c54 in aio_dispatch (ctx=0x56502440d7a0)
     at util/aio-posix.c:459
 #16 0x000056502228f742 in aio_ctx_dispatch
     (source=<optimized out>, callback=<optimized out>, user_data=<optimized out>) at util/async.c:260
 #17 0x00007f0ef5ce667d in g_main_dispatch (context=0x56502449aa40)
     at gmain.c:3176
 #18 0x00007f0ef5ce667d in g_main_context_dispatch
     (context=context@entry=0x56502449aa40) at gmain.c:3829
 #19 0x0000565022291d08 in glib_pollfds_poll () at util/main-loop.c:219
 #20 0x0000565022291d08 in os_host_main_loop_wait
     (timeout=<optimized out>) at util/main-loop.c:242
 #21 0x0000565022291d08 in main_loop_wait (nonblocking=<optimized out>)
     at util/main-loop.c:518
 #22 0x00005650220743c1 in main_loop () at vl.c:1828
 #23 0x0000565021f20a72 in main
     (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>)
     at vl.c:4504

Fix this by acquiring the AioContext at qmp_block_dirty_bitmap_add()
and qmp_block_dirty_bitmap_add().

RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1782175
Signed-off-by: Sergio Lopez <slp@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-01-27 17:19:53 +01:00
Sergio Lopez
3ea67e0883 blockdev: honor bdrv_try_set_aio_context() context requirements
bdrv_try_set_aio_context() requires that the old context is held, and
the new context is not held. Fix all the occurrences where it's not
done this way.

Suggested-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Sergio Lopez <slp@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-01-27 17:19:53 +01:00
Sergio Lopez
5b7bfe515e blockdev: unify qmp_blockdev_backup and blockdev-backup transaction paths
Issuing a blockdev-backup from qmp_blockdev_backup takes a slightly
different path than when it's issued from a transaction. In the code,
this is manifested as some redundancy between do_blockdev_backup() and
blockdev_backup_prepare().

This change unifies both paths, merging do_blockdev_backup() and
blockdev_backup_prepare(), and changing qmp_blockdev_backup() to
create a transaction instead of calling do_backup_common() direcly.

As a side-effect, now qmp_blockdev_backup() is executed inside a
drained section, as it happens when creating a blockdev-backup
transaction. This change is visible from the user's perspective, as
the job gets paused and immediately resumed before starting the actual
work.

Signed-off-by: Sergio Lopez <slp@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-01-27 17:19:53 +01:00
Sergio Lopez
2288ccfac9 blockdev: unify qmp_drive_backup and drive-backup transaction paths
Issuing a drive-backup from qmp_drive_backup takes a slightly
different path than when it's issued from a transaction. In the code,
this is manifested as some redundancy between do_drive_backup() and
drive_backup_prepare().

This change unifies both paths, merging do_drive_backup() and
drive_backup_prepare(), and changing qmp_drive_backup() to create a
transaction instead of calling do_backup_common() direcly.

As a side-effect, now qmp_drive_backup() is executed inside a drained
section, as it happens when creating a drive-backup transaction. This
change is visible from the user's perspective, as the job gets paused
and immediately resumed before starting the actual work.

Also fix tests 141, 185 and 219 to cope with the extra
JOB_STATUS_CHANGE lines.

Signed-off-by: Sergio Lopez <slp@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-01-27 17:19:53 +01:00
Sergio Lopez
471ded690e blockdev: fix coding style issues in drive_backup_prepare
Fix a couple of minor coding style issues in drive_backup_prepare.

Signed-off-by: Sergio Lopez <slp@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-01-27 17:19:53 +01:00
Max Reitz
c80d8b06cf block: Add @exact parameter to bdrv_co_truncate()
We have two drivers (iscsi and file-posix) that (in some cases) return
success from their .bdrv_co_truncate() implementation if the block
device is larger than the requested offset, but cannot be shrunk.  Some
callers do not want that behavior, so this patch adds a new parameter
that they can use to turn off that behavior.

This patch just adds the parameter and lets the block/io.c and
block/block-backend.c functions pass it around.  All other callers
always pass false and none of the implementations evaluate it, so that
this patch does not change existing behavior.  Future patches take care
of that.

Suggested-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190918095144.955-5-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28 12:00:07 +01:00
Kevin Wolf
46741111ba blockdev: Use error_report() in hmp_commit()
Instead of using monitor_printf() to report errors, hmp_commit() should
use error_report() like other places do.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2019-10-25 15:15:01 +02:00
John Snow
3264ffced3 dirty-bitmaps: remove deprecated autoload parameter
This parameter has been deprecated since 2.12.0 and is eligible for
removal. Remove this parameter as it is actually completely ignored;
let's not give false hope.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20191002232411.29968-1-jsnow@redhat.com
2019-10-17 17:53:28 -04:00
Vladimir Sementsov-Ogievskiy
5deb6cbd1f block/dirty-bitmap: add bs link
Add bs field to BdrvDirtyBitmap structure. Drop BlockDriverState
parameter from bitmap APIs where possible.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20190916141911.5255-3-vsementsov@virtuozzo.com
[Rebased on top of block-copy. --js]
Signed-off-by: John Snow <jsnow@redhat.com>
2019-10-17 17:02:32 -04:00
Vladimir Sementsov-Ogievskiy
d2c3080e41 block/qcow2: proper locking on bitmap add/remove paths
qmp_block_dirty_bitmap_add and do_block_dirty_bitmap_remove do acquire
aio context since 0a6c86d024. But this is not enough: we also must
lock qcow2 mutex when access in-image metadata. Especially it concerns
freeing qcow2 clusters.

To achieve this, move qcow2_can_store_new_dirty_bitmap and
qcow2_remove_persistent_dirty_bitmap to coroutine context.

Since we work in coroutines in correct aio context, we don't need
context acquiring in blockdev.c anymore, drop it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20190920082543.23444-4-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-10-17 17:02:32 -04:00
Vladimir Sementsov-Ogievskiy
b56a1e3175 block/dirty-bitmap: return int from bdrv_remove_persistent_dirty_bitmap
It's more comfortable to not deal with local_err.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20190920082543.23444-3-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-10-17 17:02:32 -04:00
Vladimir Sementsov-Ogievskiy
00e30f05de block/backup: use backup-top instead of write notifiers
Drop write notifiers and use filter node instead.

= Changes =

1. Add filter-node-name argument for backup qmp api. We have to do it
in this commit, as 257 needs to be fixed.

2. There are no more write notifiers here, so is_write_notifier
parameter is dropped from block-copy paths.

3. To sync with in-flight requests at job finish we now have drained
removing of the filter, we don't need rw-lock.

4. Block-copy is now using BdrvChildren instead of BlockBackends

5. As backup-top owns these children, we also move block-copy state
into backup-top's ownership.

= Iotest changes =

56: op-blocker doesn't shoot now, as we set it on source, but then
check on filter, when trying to start second backup.
To keep the test we instead can catch another collision: both jobs will
get 'drive0' job-id, as job-id parameter is unspecified. To prevent
interleaving with file-posix locks (as they are dependent on config)
let's use another target for second backup.

Also, it's obvious now that we'd like to drop this op-blocker at all
and add a test-case for two backups from one node (to different
destinations) actually works. But not in these series.

141: Output changed: prepatch, "Node is in use" comes from bdrv_has_blk
check inside qmp_blockdev_del. But we've dropped block-copy blk
objects, so no more blk objects on source bs (job blk is on backup-top
filter bs). New message is from op-blocker, which is the next check in
qmp_blockdev_add.

257: The test wants to emulate guest write during backup. They should
go to filter node, not to original source node, of course. Therefore we
need to specify filter node name and use it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20191001131409.14202-6-vsementsov@virtuozzo.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-10 10:56:18 +02:00
Max Reitz
cdf3bc934a mirror: Fix bdrv_has_zero_init() use
bdrv_has_zero_init() only has meaning for newly created images or image
areas.  If the mirror job itself did not create the image, it cannot
rely on bdrv_has_zero_init()'s result to carry any meaning.

This is the case for drive-mirror with mode=existing and always for
blockdev-mirror.

Note that we only have to zero-initialize the target with sync=full,
because other modes actually do not promise that the target will contain
the same data as the source after the job -- sync=top only promises to
copy anything allocated in the top layer, and sync=none will only copy
new I/O.  (Which is how mirror has always handled it.)

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190724171239.8764-3-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-08-19 17:13:26 +02:00
Vladimir Sementsov-Ogievskiy
319bd5edb9 block/backup: deal with zero detection
We have detect_zeroes option, so at least for blockdev-backup user
should define it if zero-detection is needed. For drive-backup leave
detection enabled by default but do it through existing option instead
of open-coding.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190730163251.755248-2-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-08-16 18:29:43 -04:00
John Snow
1a2b8b406b block/backup: support bitmap sync modes for non-bitmap backups
Accept bitmaps and sync policies for the other backup modes.
This allows us to do things like create a bitmap synced to a full backup
without a transaction, or start a resumable backup process.

Some combinations don't make sense, though:

- NEVER policy combined with any non-BITMAP mode doesn't do anything,
  because the bitmap isn't used for input or output.
  It's harmless, but is almost certainly never what the user wanted.

- sync=NONE is more questionable. It can't use on-success because this
  job never completes with success anyway, and the resulting artifact
  of 'always' is suspect: because we start with a full bitmap and only
  copy out segments that get written to, the final output bitmap will
  always be ... a fully set bitmap.

  Maybe there's contexts in which bitmaps make sense for sync=none,
  but not without more severe changes to the current job, and omitting
  it here doesn't prevent us from adding it later.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190716000117.25219-11-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-08-16 18:29:43 -04:00
John Snow
a6c9365ad4 block/backup: hoist bitmap check into QMP interface
This is nicer to do in the unified QMP interface that we have now,
because it lets us use the right terminology back at the user.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190716000117.25219-5-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-08-16 16:28:03 -04:00
John Snow
c4e4b0fa59 qapi: implement block-dirty-bitmap-remove transaction action
It is used to do transactional movement of the bitmap (which is
possible in conjunction with merge command). Transactional bitmap
movement is needed in scenarios with external snapshot, when we don't
want to leave copy of the bitmap in the base image.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190708220502.12977-3-jsnow@redhat.com
[Edited "since" version to 4.2 --js]
Signed-off-by: John Snow <jsnow@redhat.com>
2019-08-16 16:28:03 -04:00
Vladimir Sementsov-Ogievskiy
2899f41eef blockdev: reduce aio_context locked sections in bitmap add/remove
Commit 0a6c86d024 returned these locks back to add/remove
functionality, to protect from intersection of persistent bitmap
related IO with other IO. But other bitmap-related functions called
here are unrelated to the problem, and there are no needs to keep these
calls inside critical sections.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190708220502.12977-2-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-08-16 16:28:02 -04:00
John Snow
b30ffbef53 block/backup: loosen restriction on readonly bitmaps
With the "never" sync policy, we actually can utilize readonly bitmaps
now. Loosen the check at the QMP level, and tighten it based on
provided arguments down at the job creation level instead.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190709232550.10724-19-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-08-16 16:28:02 -04:00
John Snow
c8b5650178 block/backup: Add mirror sync mode 'bitmap'
We don't need or want a new sync mode for simple differences in
semantics.  Create a new mode simply named "BITMAP" that is designed to
make use of the new Bitmap Sync Mode field.

Because the only bitmap sync mode is 'on-success', this adds no new
functionality to the backup job (yet). The old incremental backup mode
is maintained as a syntactic sugar for sync=bitmap, mode=on-success.

Add all of the plumbing necessary to support this new instruction.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190709232550.10724-6-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-08-16 16:28:02 -04:00
John Snow
9203056614 blockdev-backup: utilize do_backup_common
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190709232550.10724-4-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-08-16 16:28:01 -04:00
John Snow
7b0b870bcc drive-backup: create do_backup_common
Create a common core that comprises the actual meat of what the backup API
boundary needs to do, and then switch drive-backup to use it.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190709232550.10724-3-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-08-16 16:28:01 -04:00
Markus Armbruster
54d31236b9 sysemu: Split sysemu/runstate.h off sysemu/sysemu.h
sysemu/sysemu.h is a rather unfocused dumping ground for stuff related
to the system-emulator.  Evidence:

* It's included widely: in my "build everything" tree, changing
  sysemu/sysemu.h still triggers a recompile of some 1100 out of 6600
  objects (not counting tests and objects that don't depend on
  qemu/osdep.h, down from 5400 due to the previous two commits).

* It pulls in more than a dozen additional headers.

Split stuff related to run state management into its own header
sysemu/runstate.h.

Touching sysemu/sysemu.h now recompiles some 850 objects.  qemu/uuid.h
also drops from 1100 to 850, and qapi/qapi-types-run-state.h from 4400
to 4200.  Touching new sysemu/runstate.h recompiles some 500 objects.

Since I'm touching MAINTAINERS to add sysemu/runstate.h anyway, also
add qemu/main-loop.h.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190812052359.30071-30-armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
[Unbreak OS-X build]
2019-08-16 13:37:36 +02:00
Markus Armbruster
db72581598 Include qemu/main-loop.h less
In my "build everything" tree, changing qemu/main-loop.h triggers a
recompile of some 5600 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).  It includes block/aio.h,
which in turn includes qemu/event_notifier.h, qemu/notify.h,
qemu/processor.h, qemu/qsp.h, qemu/queue.h, qemu/thread-posix.h,
qemu/thread.h, qemu/timer.h, and a few more.

Include qemu/main-loop.h only where it's needed.  Touching it now
recompiles only some 1700 objects.  For block/aio.h and
qemu/event_notifier.h, these numbers drop from 5600 to 2800.  For the
others, they shrink only slightly.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190812052359.30071-21-armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2019-08-16 13:31:52 +02:00
Vladimir Sementsov-Ogievskiy
85c9d133fb blockdev: enable non-root nodes for transaction drive-backup source
We forget to enable it for transaction .prepare, while it is already
enabled in do_drive_backup since commit a2d665c1bc
    "blockdev: loosen restrictions on drive-backup source node"

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190618140804.59214-1-vsementsov@virtuozzo.com
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-06-24 15:53:01 +02:00
Vladimir Sementsov-Ogievskiy
b23c580c94 block: drop bs->job
Drop remaining users of bs->job:
1. assertions actually duplicated by assert(!bs->refcnt)
2. trace-point seems not enough reason to change stream_start to return
   BlockJob pointer
3. Restricting creation of two jobs based on same bs is bad idea, as
   3.1 Some jobs creates filters to be their main node, so, this check
   don't actually prevent creating second job on same real node (which
   will create another filter node) (but I hope it is restricted by
   other mechanisms)
   3.2 Even without bs->job we have two systems of permissions:
   op-blockers and BLK_PERM
   3.3 We may want to run several jobs on one node one day

And finally, drop bs->job pointer itself. Hurrah!

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-06-18 16:41:10 +02:00
Vladimir Sementsov-Ogievskiy
8164102ffe blockdev: blockdev_mark_auto_del: drop usage of bs->job
We are going to remove bs->job pointer. Drop it's usage in
blockdev_mark_auto_del: instead of looking at bs->job let's check all
jobs for references to bs.

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-06-18 16:41:10 +02:00
Max Reitz
a2bb6f8c92 blockdev: Overlays are not snapshots
There are error messages which refer to an overlay node as the snapshot.
That is wrong, those are two different things.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20190603202236.1342-3-mreitz@redhat.com
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-06-14 14:16:57 +02:00
John Snow
d81e1efbea blockdev-backup: don't check aio_context too early
in blockdev_backup_prepare, we check to make sure that the target is
associated with a compatible aio context. However, do_blockdev_backup is
called later and has some logic to move the target to a compatible
aio_context. The transaction version will fail certain commands
needlessly early as a result.

Allow blockdev_backup_prepare to simply call do_blockdev_backup, which
will ultimately decide if the contexts are compatible or not.

Note: the transaction version has always disallowed this operation since
its initial commit bd8baecd (2014), whereas the version of
qmp_blockdev_backup at the time, from commit c29c1dd312, tried to
enforce the aio_context switch instead. It's not clear, and I can't see
from the mailing list archives at the time, why the two functions take a
different approach. It wasn't until later in efd7556708 (2016) that the
standalone version tried to determine if it could set the context or
not.

Reported-by: aihua liang <aliang@redhat.com>
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1683498
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20190523170643.20794-2-jsnow@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-06-14 14:16:57 +02:00
Kevin Wolf
8ed7d42fb5 blockdev: Use bdrv_try_set_aio_context() for monitor commands
Monitor commands can handle errors, so they can easily be converted to
using the safer bdrv_try_set_aio_context() function.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-06-04 15:22:22 +02:00
Kevin Wolf
d861ab3acf block: Add BlockBackend.ctx
This adds a new parameter to blk_new() which requires its callers to
declare from which AioContext this BlockBackend is going to be used (or
the locks of which AioContext need to be taken anyway).

The given context is only stored and kept up to date when changing
AioContexts. Actually applying the stored AioContext to the root node
is saved for another commit.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-06-04 15:22:22 +02:00
John Snow
4da26f138d blockdev: fix missed target unref for drive-backup
If the bitmap can't be used for whatever reason, we skip putting down
the reference. Fix that.

In practice, this means that if you attempt to gracefully exit QEMU
after a backup command being rejected, bdrv_close_all will fail and
tell you some unpleasant things via assert().

Reported-by: aihua liang <aliang@redhat.com>
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1703916
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-06-04 15:20:41 +02:00
Peter Maydell
62f6849e7a Pull request
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Merge remote-tracking branch 'remotes/jnsnow/tags/bitmaps-pull-request' into staging

Pull request

# gpg: Signature made Wed 29 May 2019 00:58:33 BST
# gpg:                using RSA key F9B7ABDBBCACDF95BE76CBD07DEF8106AAFC390E
# gpg: Good signature from "John Snow (John Huston) <jsnow@redhat.com>" [full]
# Primary key fingerprint: FAEB 9711 A12C F475 812F  18F2 88A9 064D 1835 61EB
#      Subkey fingerprint: F9B7 ABDB BCAC DF95 BE76  CBD0 7DEF 8106 AAFC 390E

* remotes/jnsnow/tags/bitmaps-pull-request:
  iotests: test external snapshot with bitmap copying
  qapi: support external bitmaps in block-dirty-bitmap-merge
  migration/dirty-bitmaps: change bitmap enumeration method

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-05-30 12:10:27 +01:00
Vladimir Sementsov-Ogievskiy
eff0829b07 qapi: support external bitmaps in block-dirty-bitmap-merge
Add new optional parameter making possible to merge bitmaps from
different nodes. It is needed to maintain external snapshots during
incremental backup chain history.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20190517152111.206494-2-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-05-28 19:33:31 -04:00
John Snow
a2d665c1bc blockdev: loosen restrictions on drive-backup source node
We mandate that the source node must be a root node; but there's no reason
I am aware of that it needs to be restricted to such. In some cases, we need
to make sure that there's a medium present, but in the general case we can
allow the backup job itself to do the graph checking.

This patch helps improve the error message when you try to backup from
the same node more than once, which is reflected in the change to test
056.

For backups with bitmaps, it will also show a better error message that
the bitmap is in use instead of giving you something cryptic like "need
a root node."

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1707303
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20190521210053.8864-1-jsnow@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-05-28 20:30:55 +02:00
Markus Armbruster
cdcd436120 blockdev: Make -drive format=help print to stdout
Command line help explicitly requested by the user should be printed
to stdout, not stderr.  We do elsewhere.  Adjust -drive to match: use
qemu_printf() instead of error_printf().  Plain printf() would be
wrong because we need to print to the current monitor for "drive_add
... format=help".

Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Max Reitz <mreitz@redhat.com>
Cc: qemu-block@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190417190641.26814-13-armbru@redhat.com>
2019-04-18 22:18:59 +02:00
Max Reitz
74ce9e466a blockdev: Check @replaces in blockdev_mirror_common
There is no reason why the constraints we put on @replaces should be
limited to drive-mirror.  Therefore, move the sanity checks from
qmp_drive_mirror() to blockdev_mirror_common() so they apply to
blockdev-mirror as well.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-19 15:50:20 +01:00
Peter Maydell
523a2a42c3 Pull request
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Merge remote-tracking branch 'remotes/jnsnow/tags/bitmaps-pull-request' into staging

Pull request

# gpg: Signature made Tue 12 Mar 2019 20:23:08 GMT
# gpg:                using RSA key F9B7ABDBBCACDF95BE76CBD07DEF8106AAFC390E
# gpg: Good signature from "John Snow (John Huston) <jsnow@redhat.com>" [full]
# Primary key fingerprint: FAEB 9711 A12C F475 812F  18F2 88A9 064D 1835 61EB
#      Subkey fingerprint: F9B7 ABDB BCAC DF95 BE76  CBD0 7DEF 8106 AAFC 390E

* remotes/jnsnow/tags/bitmaps-pull-request: (22 commits)
  tests/qemu-iotests: add bitmap resize test 246
  block/qcow2-bitmap: Allow resizes with persistent bitmaps
  block/qcow2-bitmap: Don't check size for IN_USE bitmap
  docs/interop/qcow2: Improve bitmap flag in_use specification
  bitmaps: Fix typo in function name
  block/dirty-bitmaps: implement inconsistent bit
  block/dirty-bitmaps: disallow busy bitmaps as merge source
  block/dirty-bitmaps: prohibit removing readonly bitmaps
  block/dirty-bitmaps: prohibit readonly bitmaps for backups
  block/dirty-bitmaps: add block_dirty_bitmap_check function
  block/dirty-bitmap: add inconsistent status
  block/dirty-bitmaps: add inconsistent bit
  iotests: add busy/recording bit test to 124
  blockdev: remove unused paio parameter documentation
  block/dirty-bitmaps: move comment block
  block/dirty-bitmaps: unify qmp_locked and user_locked calls
  block/dirty-bitmap: explicitly lock bitmaps with successors
  nbd: change error checking order for bitmaps
  block/dirty-bitmap: change semantics of enabled predicate
  block/dirty-bitmap: remove set/reset assertions against enabled bit
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

# Conflicts:
#	tests/qemu-iotests/group
2019-03-13 17:30:34 +00:00
Alberto Garcia
1479c730c7 block: Add an 'x-blockdev-reopen' QMP command
This command allows reopening an arbitrary BlockDriverState with a
new set of options. Some options (e.g node-name) cannot be changed
and some block drivers don't allow reopening, but otherwise this
command is modelled after 'blockdev-add' and the state of the reopened
BlockDriverState should generally be the same as if it had just been
added by 'blockdev-add' with the same set of options.

One notable exception is the 'backing' option: 'x-blockdev-reopen'
requires that it is always present unless the BlockDriverState in
question doesn't have a current or default backing file.

This command allows reconfiguring the graph by using the appropriate
options to change the children of a node. At the moment it's possible
to change a backing file by setting the 'backing' option to the name
of the new node, but it should also be possible to add a similar
functionality to other block drivers (e.g. Quorum, blkverify).

Although the API is unlikely to change, this command is marked
experimental for the time being so there's room to see if the
semantics need changes.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-12 20:30:14 +01:00
Vladimir Sementsov-Ogievskiy
cb8aac3783 qapi: drop x- from x-block-latency-histogram-set
Drop x- and x_ prefixes for latency histograms and update version to
4.0

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-12 20:30:08 +01:00
Eric Blake
796a3798ab bitmaps: Fix typo in function name
Commit a88b179f introduced the ability to set and query bitmap
persistence, but with an atypical spelling.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 20190308205845.25734-1-eblake@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-03-12 12:05:49 -04:00
John Snow
c3edf13cd1 block/dirty-bitmaps: prohibit removing readonly bitmaps
Remove is an inherently RW operation, so this will fail anyway, but
we can fail it very quickly instead of trying and failing, so do so.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190301191545.8728-6-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-03-12 12:05:49 -04:00
John Snow
a54a0c113b block/dirty-bitmaps: prohibit readonly bitmaps for backups
drive and blockdev backup cannot use readonly bitmaps, because the
sync=incremental mechanism actually edits the bitmaps on success.

If you really want to do this operation, use a copied bitmap.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190301191545.8728-5-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-03-12 12:05:49 -04:00
John Snow
3ae96d6684 block/dirty-bitmaps: add block_dirty_bitmap_check function
Instead of checking against busy, inconsistent, or read only directly,
use a check function with permissions bits that let us streamline the
checks without reproducing them in many places.

Included in this patch are permissions changes that simply add the
inconsistent check to existing permissions call spots, without
addressing existing bugs.

In general, this means that busy+readonly checks become BDRV_BITMAP_DEFAULT,
which checks against all three conditions. busy-only checks become
BDRV_BITMAP_ALLOW_RO.

Notably, remove allows inconsistent bitmaps, so it doesn't follow the pattern.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190301191545.8728-4-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-03-12 12:05:49 -04:00
John Snow
2f158ca7b6 blockdev: remove unused paio parameter documentation
This field isn't present anymore.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190223000614.13894-10-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-03-12 12:05:48 -04:00
John Snow
27a1b301a4 block/dirty-bitmaps: unify qmp_locked and user_locked calls
These mean the same thing now. Unify them and rename the merged call
bdrv_dirty_bitmap_busy to indicate semantically what we are describing,
as well as help disambiguate from the various _locked and _unlocked
versions of bitmap helpers that refer to mutex locks.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190223000614.13894-8-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-03-12 12:05:48 -04:00
Vladimir Sementsov-Ogievskiy
af0a226504 qapi: move to QOM path for x-block-latency-histogram-set
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-12 14:26:49 +01:00
Andrey Shinkevich
9ac404c523 block: iterate_format with account of whitelisting
bdrv_iterate_format (which is currently only used for printing out the
formats supported by the block layer) doesn't take format whitelisting
into account.

This creates a problem for tests: they enumerate supported formats to
decide which tests to enable, but then discover that QEMU doesn't let
them actually use some of those formats.

To avoid that, exclude formats that are not whitelisted from
enumeration, if whitelisting is in use.  Since we have separate
whitelists for r/w and r/o, take this a parameter to
bdrv_iterate_format, and print two lists of supported formats (r/w and
r/o) in main qemu.

Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-08 12:26:45 +01:00
Max Reitz
f30c66ba6e block: Use bdrv_refresh_filename() to pull
Before this patch, bdrv_refresh_filename() is used in a pushing manner:
Whenever the BDS graph is modified, the parents of the modified edges
are supposed to be updated (recursively upwards).  However, that is
nonviable, considering that we want child changes not to concern
parents.

Also, in the long run we want a pull model anyway: Here, we would have a
bdrv_filename() function which returns a BDS's filename, freshly
constructed.

This patch is an intermediate step.  It adds bdrv_refresh_filename()
calls before every place a BDS.filename value is used.  The only
exceptions are protocol drivers that use their own filename, which
clearly would not profit from refreshing that filename before.

Also, bdrv_get_encrypted_filename() is removed along the way (as a user
of BDS.filename), since it is completely unused.

In turn, all of the calls to bdrv_refresh_filename() before this patch
are removed, because we no longer have to call this function on graph
changes.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190201192935.18394-2-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25 15:11:25 +01:00
John Snow
0a6c86d024 blockdev: acquire aio_context for bitmap add/remove
When bitmaps are persistent, they may incur a disk read or write when bitmaps
are added or removed. For configurations like virtio-dataplane, failing to
acquire this lock will abort QEMU when disk IO occurs.

We used to acquire aio_context as part of the bitmap lookup, so re-introduce
the lock for just the cases that have an IO penalty. Commit 2119882c removed
these locks, and I failed to notice this when we committed fd5ae4cc, so this
has been broken since persistent bitmaps were introduced.

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1672010
Reported-By: Aihua Liang <aliang@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20190218233154.19303-1-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-02-19 17:49:43 -05:00
Vladimir Sementsov-Ogievskiy
5d3b4e9946 qapi: add x-debug-query-block-graph
Add a new command, returning block nodes (and their users) graph.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20181221170909.25584-2-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-01-31 00:38:19 +01:00
John Snow
0e2b7f0983 block: remove 'x' prefix from experimental bitmap APIs
The 'x' prefix was added because I was uncertain of the direction we'd
take for the libvirt API. With the general approach solidified, I feel
comfortable committing to this API for 4.0.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20181221093529.23855-5-jsnow@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2019-01-14 10:09:46 -06:00
John Snow
360d4e4e9a blockdev: n-ary bitmap merge
Especially outside of transactions, it is helpful to provide
all-or-nothing semantics for bitmap merges. This facilitates
the coalescing of multiple bitmaps into a single target for
the "checkpoint" interpretation when assembling bitmaps that
represent arbitrary points in time from component bitmaps.

This is an incompatible change from the preliminary version
of the API.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20181221093529.23855-4-jsnow@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2019-01-14 10:09:46 -06:00
John Snow
f4de0f8c40 blockdev: abort transactions in reverse order
Presently, we abort transactions in the same order they were processed in.
Bitmap commands, though, attempt to restore backup data structures on abort.

That's not valid, they need to be aborted in reverse chronological order.

Replace the QSIMPLEQ data structure with a QTAILQ one, so we can iterate
in reverse for the abort phase of the transaction.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20181221093529.23855-2-jsnow@redhat.com>
[eblake: rebase]
Signed-off-by: Eric Blake <eblake@redhat.com>
2019-01-14 10:08:47 -06:00
Paolo Bonzini
b58deb344d qemu/queue.h: leave head structs anonymous unless necessary
Most list head structs need not be given a name.  In most cases the
name is given just in case one is going to use QTAILQ_LAST, QTAILQ_PREV
or reverse iteration, but this does not apply to lists of other kinds,
and even for QTAILQ in practice this is only rarely needed.  In addition,
we will soon reimplement those macros completely so that they do not
need a name for the head struct.  So clean up everything, not giving a
name except in the rare case where it is necessary.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-01-11 15:46:55 +01:00
Paolo Bonzini
70537ed515 qemu/queue.h: do not access tqe_prev directly
Use the QTAILQ_IN_USE macro instead, it does the same thing but the next
patch will change it to a different definition.

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-01-11 15:46:54 +01:00
Markus Armbruster
b2322003b6 error: Remove NULL checks on error_propagate() calls
Patch created mechanically by rerunning:

  $  spatch --sp-file scripts/coccinelle/error_propagate_null.cocci \
            --macro-file scripts/cocci-macro-file.h \
            --dir . --in-place

Whitespace tidied up manually.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20181213173113.11211-1-armbru@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2018-12-18 14:57:48 +01:00
Alberto Garcia
1b57774f79 block: Use bdrv_reopen_set_read_only() in external_snapshot_commit()
This patch replaces the bdrv_reopen() call that set and remove the
BDRV_O_RDWR flag with the new bdrv_reopen_set_read_only() function.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-12-14 11:55:02 +01:00
Alberto Garcia
051a60f6a3 block: Use bdrv_reopen_set_read_only() in qmp_change_backing_file()
This patch replaces the bdrv_reopen() calls that set and remove the
BDRV_O_RDWR flag with the new bdrv_reopen_set_read_only() function.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-12-14 11:55:02 +01:00
Peter Maydell
d52e1a0e96 blockdev: Consistently use snapshot_node_name in external_snapshot_prepare()
In the function external_snapshot_prepare() we have a
BlockdevSnapshotSync struct, which has the usual combination
of has_snapshot_node_name and snapshot_node_name fields for an
optional field. We set up a local variable
        const char *snapshot_node_name =
            s->has_snapshot_node_name ? s->snapshot_node_name : NULL;

and then mostly use "if (!snapshot_node_name)" for checking
whether we have a snapshot node name. The exception is that in
one place we check s->has_snapshot_node_name instead. This
confuses Coverity (CID 1396473), which thinks it might be
possible to get here with s->has_snapshot_node_name true but
snapshot_node_name NULL, and warns that the call to
qdict_put_str() will segfault in that case.

Make the code consistent and unconfuse Coverity by using
the same check for this conditional that we do in the rest
of the surrounding code.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-11-12 17:46:57 +01:00
zhenwei pi
63d5341f85 blockdev: handle error on block latency histogram set error
Function block_latency_histogram_set may return error, but qapi ignore this.
This can be reproduced easily by qmp command:
virsh qemu-monitor-command INSTANCE '{"execute":"x-block-latency-histogram-set",
"arguments":{"device":"drive-virtio-disk1","boundaries":[10,200,40]}}'
In fact this command does not work, but we still get success result.

qmp_x_block_latency_histogram_set is a batch setting API, report error ASAP.

Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-11-12 17:46:57 +01:00
Kevin Wolf
9384a444f6 block: Make auto-read-only=on default for -drive
While we want machine interfaces like -blockdev and QMP blockdev-add to
add as little auto-detection as possible so that management tools are
explicit about their needs, -drive is a convenience option for human
users. Enabling auto-read-only=on by default there enables users to use
read-only images for read-only guest devices without having to specify
read-only=on explicitly. If they try to attach the image to a read-write
device, they will still get an error message.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2018-11-05 15:09:55 +01:00
Kevin Wolf
e35bdc123a block: Add auto-read-only option
If a management application builds the block graph node by node, the
protocol layer doesn't inherit its read-only option from the format
layer any more, so it must be set explicitly.

Backing files should work on read-only storage, but at the same time, a
block job like commit should be able to reopen them read-write if they
are on read-write storage. However, without option inheritance, reopen
only changes the read-only option for the root node (typically the
format layer), but not the protocol layer, so reopening fails (the
format layer wants to get write permissions, but the protocol layer is
still read-only).

A simple workaround for the problem in the management tool would be to
open the protocol layer always read-write and to make only the format
layer read-only for backing files. However, sometimes the file is
actually stored on read-only storage and we don't know whether the image
can be opened read-write (for example, for NBD it depends on the server
we're trying to connect to). This adds an option that makes QEMU try to
open the image read-write, but allows it to degrade to a read-only mode
without returning an error.

The documentation for this option is consciously phrased in a way that
allows QEMU to switch to a better model eventually: Instead of trying
when the image is first opened, making the read-only flag dynamic and
changing it automatically whenever the first BLK_PERM_WRITE user is
attached or the last one is detached would be much more useful
behaviour.

Unfortunately, this more useful behaviour is also a lot harder to
implement, and libvirt needs a solution now before it can switch to
-blockdev, so let's start with this easier approach for now.

Instead of adding a new auto-read-only option, turning the existing
read-only into an enum (with a bool alternate for compatibility) was
considered, but it complicated the implementation to the point that it
didn't seem to be worth it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2018-11-05 15:09:55 +01:00
John Snow
b27a6b8b32 block/backup: prohibit backup from using in use bitmaps
If the bitmap is frozen, we shouldn't touch it.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20181002230218.13949-6-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2018-10-29 16:23:16 -04:00